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Rivaroxaban is one of the new oral anticoagulants (NOAC) for preventing stroke and systemic embolism in patients with non-valvular atrial fibrillation. It has clear pharmacokinetic parameters, stable plasma concentration, less drug-drug interaction and higher compliance of patients. However, the discrepancy of pharmacokinetics between individuals and drug-induced hemorrhage events frequently occur clinically, therefore the association of gene polymorphism with drug metabolism has become a research hotspot. This article reviews the research progress on pharmacokinetic characteristics of rivaroxaban and its relationship with gene polymorphism, to provide a reference for the individualized rational use of rivaroxaban.
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Objective:To verify the accuracy of the International Warfarin Pharmacogenetics Consortium(IWPC)model, identify the effects of genetic and clinical factors on steady-state doses of Warfarin, and establish a Warfarin dose prediction model for the Han-Chinese population aged 75 years and over under the guidance of pharmacogenetics.Methods:A total of 544 Han-Chinese patients receiving Warfarin therapy for atrial fibrillation were divided into two groups: those aged 75 years and over(n=164)and those aged below 75 years(n=380). Data for the whole population and the two age groups were each substituted into the IWPC prediction model for accuracy verification.Demographic and clinical characteristics of 164 patients aged 75 years and over were recorded, and the genotypes of CYP2 C9 and VKORC1- G1639 A were detected by polymerase chain reaction.A new pharmacogenetic-guided dosing algorithm for the elderly was obtained by stepwise multiple linear regression.The accuracy of the new model was compared with that of the IWPC model. Results:The predictive accuracy of IWPC for steady-state dosing of warfarin was 35.47% in all subjects, 33.75% in 164 subjects aged below 75 years, and only 28.70% in subjects aged 75 years and over, respectively.In 164 subjects aged 75 years and over, three genotypes of *1/*1, *1/*3 and *1/*2 were detected in CYP2 C9 polymorphism, and the CYP2 C9*1/*1 genotype was the most common one, with a frequency of 87.80%(144/164), followed by the CYP2 C9*1/*3 genotype, at 11.59%(19/164). GG, GA and AA genotypes were detected in VKORC1 polymorphism, among which the AA genotype accounted for 82.32%(135/164)and the GG genotype accounted for only 1.83%(3/164). The steady state dose for Warfarin in patients with the wild-type CYP2 C9*1/*1 was higher than in those with the heterozygote CYP2 C9*1/*3 and *1/*2(3.18±0.86 mg/d vs.2.27±0.51 mg/d, t=5.637, P<0.05). Patients with a mutant homozygotic AA genotype of VKORC1 required lower maintenance doses than those with the heterozygotic GA and GG genotypes(2.96±0.66 mg/d vs. 3.59±1.43 mg/d, t=-2.092, P<0.05). The steady-state dose for Warfarin in subjects carrying CYP2 C9 (*1/*2 or *3)and VKORC1 (GA and GG)was(2.00±0.63)mg/d, lower than in those carrying other genotype combinations( P<0.05). We established a new Warfarin dosing algorithm for elderly subjects aged 75 years and over containing height, creatinine, amiodarone usage, CYP2 C9 and VKORC1 mutants, and the accuracy of the new model was 56.0%, which could explain 56.0% of individual variability, and the accuracy was higher than that of the IWPC algorithm(56.0% vs. 45.8%, P<0.05). Conclusions:Polymorphisms of CYP2 C9 and VKORC1 clearly affect the steady-state dose for Warfarin in the elderly Han-Chinese population aged 75 years and over.A combination of pharmacogenomics with clinical factors can better guide warfarin medication in Han-Chinese people aged 75 years and over.
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AIM: To investigate the effect of curcumin on oxidized low-density lipoprotein (ox-LDL)-induced injury of human aortic endothelial cells (HAECs).METHODS: HAECs were pre-treated with curcumin at different concentrations and then treated with ox-LDL.The cell viability was assessed by MTT assay.The cell proliferation ability was analyzed by EdU assay.ELISA was used to determine the concentrations of interleukin-6 (IL-6), transforming growth factor β1 (TGFβ1), high mobility group box-1 protein (HMGB1) and secretory receptor for advanced glycation end products (sRAGE) in the HAEC culture medium.The binding activity of peroxisome proliferator-activated receptor γ (PPARγ) was evaluated by electrophoretic mobility shift assay.The protein levels of HO-1, HMGB1, RAGE,IL-6,TGFβ1 and phosphorylated PPARγ in the HAECs were determined by Western blot.RESULTS: The viability and the proliferation ability decreased significantly in the HAECs treated with ox-LDL.The PPARγ/HO-1 signaling pathway was inhibited while its down-stream HMGB1/RAGE signaling pathway was activated by ox-LDL.The levels of IL-6, TGFβ1, HMGB1 and sRAGE were increased.Pre-treatment with curcumin activated PPARγ/HO-1 signaling pathway and inhibited HMGB1/RAGE signaling pathway in ox-LDL treated HAECs in a concentration-dependent manner.The levels of IL-6, TGFβ1, HMGB1 and sRAGE were also decreased dramatically by pre-treatment of curcumin in a concentration-dependent manner.CONCLUSION: ox-LDL induces HAEC damage by inhibiting PPARγ/HO-1 to activate HMGB1/RAGE inflammatory signaling.Curcumin exerts protective effect on ox-LDL treated HAECs via activating PPARγ/HO-1 signaling pathway.
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AIM: To investigate the inhibitory effect of L-carnitine on high glucose-induced apoptosis of human aortic endothelial cells (HAECs) and the molecular mechanisms.METHODS: The apoptosis of HAECs was induced by high-glucose incubation.HAECs were treated with L-carnitine at different concentrations (50, 100 and 200 μmol/L).The cell viability was measured by MTT assay.The cell apoptosis was assessed by Hoechst 33258 staining and flow cytometry.Colorimetric method was employed to detect the caspase-3 activity in the HAECs.The protein expression and phosphorylation levels were determined by Western blot.RESULTS: High-glucose incubation dramatically decreased the cell viability and induced apoptosis.The protein kinase R-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme-1 (IRE1) and activating transcription factor 6 (ATF6) signaling pathways of endoplasmic reticulum stress were activated to induce cell apoptosis via down-stream caspase-4/3 cascade.However, L-carnitine treatment significantly attenuated the cell apoptosis and increased the cell viability in a concentration-dependent manner.L-carnitine also significantly suppressed endoplasmic reticulum stress and ATF6 signaling in high glucose-incubated HAECs without attenuating PERK and IRE1 signaling.The expression of site-1 protease (S1P) and site-2 protease (S2P) was inhibited by L-carnitine treatment, thus decreasing pro-apoptotic factor ATF6 p50 produced by ATF6 cleavage.CONCLUSION: L-carnitine inhibits high glucose-induced apoptosis of HAECs by inhibiting ATF6 signaling.